Polyester based on poly(trimethylene terephthalate)

ABSTRACT

A polyester based on poly(trimethylene terephthalate) consisting essentially of trimethylene terephthalate repeating units, comprising at least one kind of compound selected from the group consisting of alkali metal compounds, alkaline earth metal compounds and manganese compounds in an amount of 10 to 150 ppm expressed in terms of the metal element in a molar ratio of the total amount of elements of the contained alkali metal elements, alkaline earth metal elements and manganese element to the amount of the contained phosphorus element within the range of the following formula (I):
 
0≦P/M≦1  (I)
 
wherein, P is the molar amount of the phosphorus element in the polyester; M is the total amount of the alkali metal elements, alkaline earth metal elements and manganese element.

TECHNICAL FIELD

The present invention relates to a polyester. More particularly, thepresent invention relates to a polyester based on poly(trimetyleneterephthalate) slightly causing yellowing after light irradiation andhaving improved light resistance.

BACKGROUND ART

As well known, polyesters have been widely used as fibers, resins, filmsand the like due to excellent performances thereof. Especially,polyester fibers comprising polyethylene terephthalate and havingexcellent dimensional stability, heat, chemical and light resistancesand the like have been utilized in various fields irrespective ofclothing and nonclothing uses.

In the situation, attention has recently been paid to polyester fibersbased on polytrimethylene terephthalate and a woven or a knitted fabriccomprising the polyester fibers so as to exhibit hand and dyeabilitywhich are difficult to realize from the conventional polytrimethyleneterephthalate [for example, JP-A (hereunder, JP-A means “JapaneseUnexamined Patent Publication”) 11-200175]. The polyester fibers basedon the polytrimethylene terephthalate, however, have problems thatdegree of yellowing in light irradiation is greater than that ofpolyethylene terephthalate and light resistance is inferior to that ofthe polyethylene terephthalate.

As a method for improving the whiteness of the polytrimethyleneterephthalate, the addition of a phosphorus compound duringpolymerization is proposed in, for example WO99/11709. An improvement inlight resistance, however, cannot be expected by the method though themelt stability is improved.

On the other hand, for example, JP-A 3-234812 describes a method foradding a manganese compound, an antimony compound and a germaniumcompound to polyethylene terephthalate as a method for improving thelight resistance of the polyester fibers. The method relates to theinhibition of the strength deterioration of the polyethyleneterephthalate fibers and is a technique different from the prevention ofyellowing, especially the prevention of yellowing of thepolytrimethylene terephthalate fibers.

U.S. Pat. No. 5,872,204 describes the use of a manganese compound as acatalyst usable together with an antimony compound catalyst as atechnique for adding a manganese compound to the polytrimethyleneterephthalate. However, there is no description of an improvement inlight resistance by the method, which has problems that foreignmaterials are readily produced in spinnerets during fiber formationbecause the antimony compound is used.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to eliminate the problemspossessed by the prior art and to provide a polyester based on thepolytrimethylene terephthalate slightly causing yellowing after lightirradiation and having improved light resistance.

BEST MODE FOR CARRYING OUT THE INVENTION

The mode for carrying out the present invention will be detailedhereinafter.

The polyester based on the polytrimethylene terephthalate is a polyesterconsisting essentially of trimethylene terephthalate repeating units.

The expression “consisting essentially of trimethylene terephthalaterepeating units” refers to “the trimethylene terephthalate repeatingunits account for 85 mole % or more, preferably 90 mole % or more in thewhole repeating units constituting the polyester.

It is necessary for the polyester of the present invention to contain atleast one kind of compound selected from the group consisting of alkalimetal compounds, alkaline earth metal compounds and manganese compoundsin an amount of 10 to 150 ppm expressed in terms of the metal element.When the content of the element is less than 10 ppm, the lightresistance of the finally obtained polyester fibers becomesinsufficient. On the other hand, when the content exceeds 150 ppm, it isundesirable that the yellowness of the polyester polymer per se isincreased and the yellowing and lowering of the molecular weight duringremelting are increased. The content of the element is preferably withinthe range of 150 to 120 ppm, especially preferably within the range of20 to 100 ppm.

Examples of the alkali metal used in the present invention includelithium, sodium, potassium, rubidium and the like. Examples of thealkaline earth metal include magnesium, calcium, strontium and the like.

Acetates, benzoates, hydrochlorides, formates, oxalates, nitrates,carbonates and the like can be used as the alkali metal compounds,alkaline earth metal compounds and manganese compounds employed in thepresent invention. Acetates and benzoates are preferable from theviewpoint of solubility in the polyester polymer. Furthermore, thecompounds may be hydrates or anhydrides.

Further, in the polyester of the present invention, it is necessary thatthe molar ratio of the total amount of elements of the contained alkalimetal elements, alkaline earth metal elements and manganese element tothe amount of the contained phosphorus element satisfies therelationship of the following formula (I):0≦P/M≦1  (I)wherein, P is the molar amount of the phosphorus element in thepolyester; M is the total molar amount of the alkali metal elements,alkaline earth metal elements and manganese element.

In the formula (I), when P/M exceeds 1, the light resistance of thefinally obtained fibers becomes insufficient. The P/M is preferablywithin the range of 0 to 0.8, especially preferably within the range of0 to 0.6.

It is preferable that the polyester of the present inventionsimultaneously satisfies the following respective requirements (a) to(d):

-   (a) the intrinsic viscosity is within the range of 0.5 to 1.6,-   (b) the content of dipropylene glycol is within the range of 0.1 to    2.0% by weight,-   (c) the content of a cyclic dimer is within the range of 0.01 to 5%    by weight and-   (d) the color b value after crystallization is within the range of    −5 to 10.

For explanation of the respective requirements, the mechanical strengthof the finally obtained fibers is sufficiently high and handleability ismore improved when the intrinsic viscosity is within the above range.The intrinsic viscosity is more preferably within the range of 0.55 to1.5, especially preferably within the range of 0.6 to 1.4.

When the content of the dipropylene glycol is within the above range,the heat resistance of the polyester and mechanical strength of thefinally obtained fibers become sufficiently high. The content of thedipropylene glycol is more preferably within the range of 0.15 to 1.8%by weight, especially preferably within the range of 0.2 to 1.5% byweight.

When the content of the cyclic dimer is within the above range, the yarnmanufacturing property of the polyester is good. The content of thecyclic dimer is more preferably within the range of 0.02 to 1.8% byweight, especially preferably within the range of 0.03 to 1.5% byweight.

In addition, when the color b value after the crystallization is withinthe above range, the appearance of the finally obtained products isimproved. The color b value is more preferably within the range of −4 to9, especially preferably within the range of −3 to 8.

The polyester based on the polytrimethylene terephthalate of the presentinvention may be copolymerized with a component other than terephthalicacid component and trimethylene glycol component in an amount within therange without deteriorating characteristics of the polyester based onthe polytrimethylene terephthalate, preferably within the range of 10mole % or less based on the whole dicarboxylic acid component.

Examples of the copolymerization components include aromaticdicarboxylic acids such as isophthalic acid, orthophthalic acid,naphthalenedicarboxylic acid, diphenyldicarboxylic acid,diphenyletherdicarboxylic acid, diphenylsulfonedicarboxylic acid,benzophenonedicarboxylic acid, phenylindanedicarboxylic acid,5-sulfoxyisophthalic acid metal salts or 5-sulfoxyisophthalic acidphosphonium salts, aliphatic glycols such as ethylene glycol,tetramethylene glycol, pentamethylene glycol, hexamethylene glycol,octamethylene glycol, decamethylene glycol, neopentylene glycol,diethylene glycol, triethylene glycol, polyethylene glycol,polytetramethylene glycol or cyclohexanediol, alicyclic glycols such as1,4-cyclohexanedimethanol or 1,4-cyclohexanediol, aromatic glycols suchas o-xylylene glycol, m-xylylene glycol, p-xylylene glycol,1,4-bis(2-hydroxyethoxy)benzene, 1,4-bis(2-hydroxyethoxyethoxy)benzene,4,4′-bis(2-hydroxyethoxy)biphenyl,4,4′-bis(2-hydroxyethoxyethoxy)biphenyl, 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane, 2,2-bis[4-(2-hydroxyethoxyethoxy)phenyl]propane,1,3-bis(2-hydroxyethoxy)benzene, 1,3-bis(2-hydroxyethoxyethoxy)benzene,1,2-bis(2-hydroxyethoxy)benzene, 1,2-bis(2-hyroxyethoxyethoxy)benzene,4,4′-bis(2-hydroxyethoxy)diphenyl sulfone or4,4′-bis(2-hyroxyethoxyethoxy)diphenyl sulfone, diphenols such ashydroquinone, 2,2-bis(4-hydroyphenyl)propane, resorcinol, catechol,dihydroxynaphthalene, dihydroxybiphenyl or dihydroxydiphenyl sulfone.One kind of the copolymerization components may be used alone or two ormore kinds may be used in combination.

The polyester based on the poly(trimethylene terephthalate) can beproduced by a conventionally known method. Namely, a transesterificationmethod for subjecting a lower alkyl ester component of terephthalic acidand a trimethylene glycol component to transesterification in thepresence of a transesterification catalyst, providing a bisglycol esterand/or its percondensate and then carrying out polymerizing reaction inthe presence of a polymerizing reaction catalyst or a directpolymerization method or the like for directly esterifying terephthalicacid with trimethylene glycol, producing an oligomer of a low degree ofpolymerization and subsequently carrying out the polymerizing reactionin the presence of the polymerizing reaction catalyst can be adopted.

The solid-phase polymerization for the purpose of increasing themolecular weight, reducing the content of terminal carboxyl groups andthe like can preferably be carried out by a conventional known method.

In the present invention, examples of compounds used as thetransesterification catalyst include manganese compounds, cobaltcompounds, calcium compounds, titanium compounds, sodium compounds,potassium compounds, zinc compounds, magnesium compounds and the like.The compounds may be used alone or two or more kinds may be used incombination. The titanium compounds used as a polycondensation catalystcan previously be added before transesterification and used as both thetransesterification catalyst and the polycondensation reaction catalyst.

Examples of preferably used titanium compounds employed as thepolymerizing reaction catalyst include a titanium tetraalkoxide alone, areaction product of at least one kind of compound selected from thegroup consisting of phthalic acid, trimellitic acid, hemimellitic acidand pyromellitic acid or anhydrides thereof with the titaniumtetraalkoxide, a reaction product of the titanium tetraalkoxide with aphosphonic acid compound, a reaction product of the titaniumtetraalkoxide with a phosphinic acid compound, a reaction product of thetitanium tetraalkoxide with a phosphate compound and a compound preparedby further carrying out reaction of the reaction product between atleast the one kind of compound selected from the group consisting ofphthalic acid, trimellitic acid, hemimellitic acid and pyromellitic acidor anhydrides thereof and the titanium tetraalkoxide with the phosphonicacid compound, phosphinic acid compound or phosphate compound. Titaniumtetrabutoxide is especially preferably used as the titaniumtetraalkoxide.

The molar ratio of the titanium tetraalkoxide to the phthalic acid,trimellitic acid, hemimellitic acid and pyromellitic acid or anhydridesthereof, phosphonic acid compound, phosphinic acid compound andphosphate compound is especially preferably about 1.5 to 2.5 based onthe titanium tetraalkoxide.

Examples of the phosphonic acid compound to be reacted with the titaniumtetraalkoxide include phenylphosphonic acid, methylposphonic acid,ethylphosphonic acid, propylphosphonic acid, isopropylphosphonic acid,butylphosphonic acid, tolylphosphonic acid, xylylphosphonic acid,biphenylphosphonic acid, naphthylphosphonic acid, anthrylphosphonicacid, 2-carboxyphenylphosphonic acid, 3-carboxyphenylphosphonic acid,4-carboxyphenylphosphonic acid, 2,3-dicarboxyphenylphosphonic acid,2,4-dicarboxyphenylphosphonic acid, 2,5-dicarboxyphenylphosphonic acid,2,6-dicarboxyphenylphosphonic acid, 3,4-dicarboxyphenylphosphonic acid,3,5-dicarboxyphenylphosphonic acid, 2,3,4-tricarboxyphenylphosphonicacid, 2,3,5-tricarboxyphenylphosphonic acid,2,3,6-tricarboxyphenylphosphonic acid, 2,4,5-tricarboxyphenylphosphonicacid, 2,4,6-tricarboxyphenylphosphonic acid and the like.

Examples of the phosphinic acid compound include phenylphosphinic acid,methylphosphinic acid, ethylphosphinic acid, propylphosphinic acid,isopropylphosphinic acid, butylphosphinic acid, tolylphosphinic acid,xylylphosphinic acid, biphenylylphosphinic acid, diphenylphosphinicacid, dimethylphosphinic acid, diethylphosphinic acid,dipropylphosphinic acid, diisopropylphosphinic acid, dibutylphosphinicacid, ditolylphosphinic acid, dixylylphosphinic acid,dibiphenylylphosphinic acid, naphthylphosphinic acid, anthrylphosphinicacid, 2-carboxyphenylphosphinic acid, 3-carboxyphenylphosphinic acid,4-carboxyphenylphosphinic acid, 2,3-dicarboxyphenylphosphinic acid,2,4-dicarboxyphenylphosphinic acid, 2,5-dicarboxyphenylphosphinic acid,2,6-dicarboxyphenylphosphinic acid, 3,4-dicarboxyphenylphosphinic acid,3,5-dicarboxyphenylphosphinic acid, 2,3,4-tricarboxyphenylphosphinicacid, 2,3,5-tricarboxyphenylphosphinic acid,2,3,6-tricarboxyphenylphosphinic acid, 2,4,5-tricarboxyphenylphosphinicacid, 2,4,6-tricarboxyphenylphosphinic acid,bis(2-carboxyphenyl)phosphinic acid, bis(3-carboxyphenyl)phosphinicacid, bis(4-carboxyphenyl)phosphinic acid,bis(2,3-dicarboxyphenyl)phosphinic acid,bis(2,4-dicarboxyphenyl)phosphinic acid,bis(2,5-dicarboxyphenyl)phosphinic acid,bis(2,6-dicarboxyphenyl)phosphinic acid,bis(3,4-dicarboxyphenyl)phosphinic acid,bis(3,5-dicarboxyphenyl)phosphinic acid,bis(2,3,4-tricarboxyphenyl)phosphinic acid,bis(2,3,5-tricarboxyphenyl)phosphinic acid,bis(2,3,6-tricarboxyphenyl)phosphinic acid,bis(2,4,5-tricarboxyphenyl)phosphinic acid,bis(2,4,6-tricarboxyphenyl)phosphinic acid and the like.

Furthermore, examples of the phosphate compound include monoalkylphosphates and monaryl phosphates such as monomethyl phosphate,monoethyl phosphate, monotrimethyl phosphate, mono-n-butyl phosphate,monohexyl phosphate, monoheptyl phosphate, monooctyl phosphate,monononyl phosphate, monodecyl phosphate, monododecyl phosphate,monolauryl phosphate, monooleyl phosphate, monotetradecyl phosphate,monophenyl phosphate, monobenzyl phosphate, mono(4-dodecyl)phenylphosphate, mono(4-methylphenyl) phosphate, mono(4-ethylphenyl)phosphate, mono(4-propylphenyl) phosphate, mono(4-dodecylphenyl)phosphate, monotolyl phosphate, monoxylyl phosphate, monobiphenylphosphate, mononaphthyl phosphate, monoanthryl phosphate and the like.

The polyester based on the poly(trimethylene terephthalate) of thepresent invention, if necessary, may contain a small amount of anadditive, for example, a lubricant, a pigment, a dye, an antioxidant, asolid-phase polymerization accelerator, a fluorescent brightener, anantistatic agent, an antimicrobial agent, an ultraviolet light absorber,a light stabilizer, a heat stabilizer, a light screen, a delusteringagent and the like.

In the polyester of the present invention, at least one kind of compoundselected from the group consisting of alkali metal compounds alkalineearth metal compounds and manganese compounds is contained at a highconcentration exceeding 150 ppm to 10000 ppm expressed in terms of themetal element to provide a polyester containing the metal compound atthe high concentration. With a polyester based on the poly(trimethyleneterephthalate), is melt kneaded 0.5 to 50% by weight of the polyestercontaining the metal compound at the high concentration. Thereby, atleast the one kind of compound selected from the group consisting of thealkali metal compounds, the alkaline earth metal compounds and themanganese compounds may be contained so as to provide at least the onecompound in an amount of 10 to 150 ppm expressed in terms of the metalelement in the polyester based on the poly(trimethylene terephthalate).

In this case, when the amount of the polyester containing the metalcompound at the high concentration is 0.5% by weight or less, it isdifficult to uniformly disperse the metal compound in the polyester.When the amount exceeds 50% by weight, the production efficiency of thepolyester based on the poly(trimethylene terephthalate) is inferiorbecause the amount used of the polyester containing the metal compoundat the high concentration is too large. When the polyester containingthe metal compound at the high concentration is used, the amount thereofused is preferably within the range of 0.7 to 40% by weight, morepreferably within the range of 1 to 30% by weight.

When the polyester containing the metal compound at the highconcentration is to be used, the necessity for using a large amount ofthe polyester containing the metal compound at the high concentrationarises in order to maintain the light resistance of the finally obtainedfibers at a sufficient level if the content of the metal element is 150ppm or less. On the other hand, when the content of the metal elementexceeds 10000 ppm, it is difficult to control the quality of the finallyobtained fibers because the yellowness of the polyester containing themetal compound at the high concentration per se is increased and furtherthe lowering of molecular weight by thermal decomposition is marked ifthe content exceeds 10000 ppm. Thereby, the content of the metal elementis more preferably within the range of 300 to 8000 ppm, especiallypreferably within the range of 500 to 5000 ppm.

Methods for melt kneading the polyester containing the metal compound atthe high concentration with the polyester based on the poly(trimethyleneterephthalate) are not especially limited; however, examples of themethods include a method for adding a solid or a molten polyestercontaining the metal compound at the high concentration to the polyesterbased on the poly(trimethylene terephthalate) melted with, for example atwin-screw extruder using a side feeder or the like, a method for chipblending the polyester based on the poly(trimethylene terephthalate)with the polyester containing the metal compound at the highconcentration and then melt kneading the blended chips, a method foradding chips of the polyester containing the metal compound at the highconcentration into a polymerizing reaction vessel in a polymerizingreaction stage of the polyester based on the poly(trimethyleneterephthalate polymerized by a batch method and the like.

The fibers comprising the polyester based on the poly(trimethyleneterephthalate) of the present invention may be produced by melt spinningthe polyester based on the poly(trimethylene terephthalate) at atemperature within the range of 238 to 275° C., and yarn breakage duringthe spinning does not occur when the melt spinning temperature is withinthe range. The melt spinning temperature is preferably within the rangeof 239 to 270° C., especially preferably within the range of 240 to 265°C. The spinning speed when the melt spinning is carried out may be setwithin the range of 400 to 5000 m/min. When the spinning speed is withinthe range, the strength of the obtained fibers is sufficient and thefibers can stably be wound. The spinning speed is more preferably withinthe range of 500 to 4700 m/min, especially preferably within the rangeof 600 to 4500 m/min.

The shape of a spinneret used during the spinning is not especiallylimited, and any of a circular, a modified cross-section, a solid, ahollow shapes and the like can be adopted.

A polyester dawn yarn based on the poly(trimethylene terephthalate) inthe present invention can be obtained by winding the polyester fibers ofthe poly(trimethylene terephthalate) or, without winding the polyesterfibers once, and continuously subjecting the fibers to the drawingtreatment.

The polyester fibers and polyester drawn yarn based on thepoly(trimethylene terephthalate) of the present invention have anintrinsic viscosity preferably within the range of 0.5 to 1.5. When theintrinsic viscosity is within the range, the mechanical strength of thefinally obtained fibers is sufficiently high and handling is improved.The intrinsic viscosity is more preferably within the range of 0.52 to1.4, especially preferably within the range of 0.55 to 1.3.

A fabric having a value of an increase in color b value of 2 or lessafter irradiation at a humidity of 50% RH and 60° C. for 80 hours with asunshine weatherometer can be obtained by using the polyester fibersand/or polyester drawn yarn of the present invention.

EXAMPLES

The present invention will be explained more specifically hereafter withexamples. The present invention, however, is not limited by the examplesat all. Respective values in the examples were measured according to thefollowing methods.

(1) Intrinsic Viscosity:

The intrinsic viscosity was obtained by carrying out measurements at 35°C. according to a conventional method using o-chlorophenol as a solvent.

(2) Measurements of Calcium Content, Rubidium Content, ManganeseContent, Cobalt Content and Phosphorus Content in Polyester:

A sample polymer was thermally melted to prepare a circular disk, andthe contents were obtained according to a conventional method using afluorescent X-ray apparatus manufactured by Rigaku Corporation.

(3) Measurements of Sodium Content, Potassium Content, Lithium Contentand Magnesium Content in Polyester:

One g of a sample polymer was dissolved in 10 ml of o-chlorophenol,mixed with 20 ml of 0.5 N-HCl and allowed to stand overnight. Thecontents were obtained by carrying out measurements of the supernatantHCl solution according to a conventional method using Z-6100 PolarizedZeeman Atomic Absorption Spectrophotometer manufactured by Hitachi, Ltd.

(4) Content of Dipropylene Glycol

A sample polymer, together with an excessive amount of methanol, wassealed in a tube and subjected to methanolysis under conditions of 260°C. for 4 hours in an autoclave, and the amount of dipropylene glycol inthe decomposition product was determined according to a conventionalmethod using a gas chromatography (HP6890 Series GC System manufacturedby Hewlett-Packard Company). The weight percentage of the dipropyleneglycol based on the weight of the measured polymer was obtained.

(5) Content of Cyclic Dimer

In 1 ml of hexafluoroisopropanol, was dissolved 1 mg of a samplepolymer. A sample solution prepared by diluting the resulting solutionwith chloroform until the volume reached 10 ml was injected by using anapparatus in which two GPC columns TSK gel G2000H8 manufactured byWaters Corporation were connected in a model 486 liquid chromatographmanufactured by Waters Corporation. Chloroform was used as a developingsolvent, and the content of the cyclic dimer of the polymer was obtainedfrom a calibration curve of the previously prepared standard cyclicdimer.

(6) Color b Value After Crystallization

The color of chips was obtained after drying at 130° C. for 2 hours andthe color of fibers was obtained after knitting the fibers into aknitted fabric according to a conventional method using acolor-difference meter (model: CR-200) manufactured by Minolta Co., Ltd.

(7) Tensile Strength and Tensile Elongation

Measurements were carried out according to the method described in JISL1070.

(8) Evaluation of Light Resistance

A sample prepared by knitting fibers into a knitted fabric wasirradiated under conditions of 60° C., 80 hours and a humidity of 50% RHwithout rainfall using a sunshine weatherometer (manufactured by SugaTest Instruments Co., Ltd.). The color b values of the sample before andafter the irradiation were measured to calculate an increase in color bvalue.

Reference Example 1 Production of a Catalyst Comprising a ReactionProduct of Titanium Tetrabutoxide with Trimellitic Anhydride

Tetrabutoxytitnium in an amount of 0.5 mole based on 1 mole oftrimellitic anhydride was added to a trimethylene glycol solution (0.2%)of trimellitic anhydride, and the resulting mixture was kept at 80° C.under atmospheric pressure in air and reacted for 60 minutes. Theresultant reaction mixture was then cooled to normal temperature, andthe produced catalyst was recrystallized with acetone in an amount of 10times. The deposited substance was filtered through a filter paper anddried at 100° C. for 2 hours to provide the objective catalyst.

Reference Example 2 Production of a Catalyst Comprising a ReactionProduct of Titanium Tetrabutoxide with Phenylphosphonic Acid

Tetrabutoxytitanium in an amount of 0.5 mole based on 1 mole ofphenylphosphonic acid was added to a trimethylene glycol solution (0.2%)of the phenylphosphonic acid, and the resulting mixture was kept at 120°C. under atmospheric pressure in air and reacted for 60 minutes toafford the objective catalyst as a white slurry.

Reference Example 3 Production of a Catalyst Comprising a ReactionProduct of Titanium Tetrabutoxide with Phenylphosphinic Acid

Tetrabutoxytitanium in an amount of 0.5 mole based on 1 mole ofphenylphosphinic acid was added to a trimethylene glycol solution (0.2%)of the phenylphosphinic acid, and the resulting mixture was kept at 120°C. under atmospheric pressure in air and reacted for 60 minutes toprovide the objective catalyst as a white slurry.

Example 1

A reactor equipped with a stirrer, a rectifying column and a methanoldistilling off condenser was charged with 100 parts by weight ofdimethyl terephthalate, 70.5 parts by weight of trimethylene glycol and0.0316 part by weight of manganese acetate tetrahydrate as atransesterification catalyst, and transesterification was carried outwhile slowly heating up the mixture from 140° C. and distilling offmethanol produced as a result of the reaction to the outside of thesystem. The internal temperature reached 210° C. after the passage of 3hours from the start of reaction.

To the resulting reaction product, was added 0.0526 part by weight oftitanium tetrabutoxide as a polymerizing reaction catalyst. Theresulting mixture was then transferred to another reactor equipped witha stirrer and a glycol distilling off condenser, and polymerizingreaction was carried out while slowly heating up the mixture from 210°C. to 265° C. and reducing the pressure from atmospheric pressure to ahigh vacuum of 70 Pa. The polymerizing reaction was finished when theintrinsic viscosity reached 0.75 while tracing the melt viscosity of thereaction system.

The molten polymer was extruded from the bottom of the reactor in astrand form into cooling water and cut with a strand cutter into chips.Table 1 shows the results.

The resultant chips were melted at 250° C. using an extrusion spinningmachine equipped with a spinneret provided with 36 circular spinningholes having a hole diameter of 0.27 mm and spun at a throughput of 34g/min and a takeoff speed of 2400 m/min. The resulting undrawn yarn wasfed to a drawing treating machine equipped with a heating roller at 60°C. and a plate heater at 160° C. and subjected to drawing treatment at adraw ratio of 1.7 times to provide an 83 dtex/36 filament drawn yarn.Table 2 shows the results.

Example 2

Procedures were carried out in the same manner as in Example 1, exceptthat 0.0316 part by weight of manganese acetate tetrahydrate and 0.0038part by weight of cobalt acetate tetrahydrate were used in combinationas a transesterification catalyst in Example 1. Tables 1 and 2 show theresults.

Example 3

Procedures were carried out in the same manner as in Example 1, exceptthat the polymerizing reaction catalyst was changed from the titaniumtetrabutoxide and the catalyst prepared in Reference Example 1 in anamount of 30 mmole % expressed in terms of titanium atom was used inExample 1. Tables 1 and 2 show the results.

Example 4

Procedures were carried out in the same manner as in Example 1, exceptthat the polymerizing reaction catalyst was changed from the titaniumtetrabutoxide and the catalyst prepared in Reference Example 2 in anamount of 30 mmole % expressed in terms of titanium atom was used inExample 1. Tables 1 and 2 show the results.

Example 5

Procedures were carried out in the same manner as in Example 1, exceptthat the polymerizing reaction catalyst was changed from the titaniumtetrabutoxide and the catalyst prepared in Reference Example 3 in anamount of 30 mmole % expressed in terms of titanium atom was used inExample 1. Tables 1 and 2 show the results.

Example 6

Procedures were carried out in the same manner as in Example 1, exceptthat 0.009 part by weight of trimethyl phosphate was added aftercompleting the transesterification in Example 1. Tables 1 and 2 show theresults.

Example 7

Procedures were carried out in the same manner as in Example 2, exceptthat 0.009 part by weight of trimethyl phosphate was added aftercompleting the transesterification in Example 2. Tables 1 and 2 show theresults.

Example 8

The chips obtained by the procedures in Example 1 were melted at 250° C.with an extrusion spinning machine equipped with a spinneret providedwith 36 circular spinning holes having a hole diameter of 0.27 mm andspun at a throughput of 36 g/min and a takeoff speed of 3600 m/min. Theresulting undrawn yarn was fed to a drawing treating machine equippedwith a heating roller at 60° C. and a plate heater at 160° C. andsubjected to drawing treatment at a draw ratio of 1.2 times to afford an83 dtex/36 filament drawn yarn. Tables 1 and 2 show the results.

Example 9

The chips obtained by the procedures in Example 1 were melted with anextrusion spinning machine equipped with a spinneret provided with 36circular spinning holes having a hole diameter of 0.27 mm, spun at athroughput of 34 g/min and a takeoff speed of 2400 m/min and, withoutbeing wound once, fed to a drawing treating machine equipped with aheating roller at 60° C. and a plate heater at 160° C. and subjected todrawing treatment at a draw ratio of 1.7 times to provide an 83 dtex/36filament drawn yarn. Tables 1 and 2 show the results.

Example 10

A reactor equipped with a stirrer, a rectifying column and a methanoldistilling off condenser was charged with 100 parts by weight ofdimethyl terephthalate, 70.5 parts by weight of trimethylene glycol and0.0526 part by weight of titanium tetrabutoxide as a catalyst andfurther 0.0126 part by weight of potassium acetate andtransesterification was carried out while slowly heating up the mixturefrom 140° C. and distilling off methanol produced as a result of thereaction. The internal temperature reached 210° C. after the passage of3 hours from the start of the reaction.

The resulting reaction product was then transferred to another reactorequipped with a stirrer and a glycol distilling off condenser andpolymerizing reaction was carried out while slowly heating up thereaction product from 210° C. to 265° C. and reducing the pressure fromatmospheric pressure to a high vacuum of 70 Pa. The polymerizingreaction was finished when the intrinsic viscosity reached 0.75 whiletracing the melt viscosity of the reaction system.

The molten polymer was then extruded from the bottom of the reactor in astrand form into cooling water and cut with a strand cutter into chips.Table 1 shows the results.

The obtained chips were melted at 250° C. with an extrusion spinningmachine equipped with a spinneret provided with 36 circular spinningholes having a hole diameter of 0.27 mm at a throughput of 34 g/min anda takeoff speed of 2400 m/min. The resulting undrawn yarn was fed to adrawing treating machine equipped with a heating roller at 60° C. and aplate heater at 160° C. and subjected to drawing treatment at a drawratio of 1.7 times to afford an 83 dtex/36 filament drawn yarn. Table 2shows the results.

Example 11

Procedures were carried out in the same manner as in Example 10, exceptthat the amount of the potassium acetate used was changed from 0.0126part by weight and 0.00758 part by weight of the potassium acetate wasused in Example 10. Tables 1 and 2 show the results.

Example 12

Procedures were carried out in the same manner as in Example 10, exceptthat 0.0126 part by weight of potassium acetate was changed and 0.0175part by weight of sodium acetate trihydrate was used in Example 10.Tables 1 and 2 show the results.

Example 13

Procedures were carried out in the same manner as in Example 10, exceptthat 0.0126 part by weight of the potassium acetate was changed and0.0085 part by weight of lithium acetate was used in Example 10. Tables1 and 2 show the results.

Example 14

Procedures were carried out in the same manner as in Example 10, exceptthat 0.0126 part by weight of potassium acetate was changed and 0.0186part by weight of rubidium acetate was used in Example 10. Tables 1 and2 show the results.

Example 15

Procedures were carried out in the same manner as in Example 10, exceptthat 0.0126 part by weight of potassium acetate was changed and 0.0227part by weight of calcium acetate monohydrate was used in Example 10.Tables 1 and 2 show the results.

Example 16

Procedures were carried out in the same manner as in Example 10, exceptthat 0.0126 part by weight of potassium acetate was changed and 0.0276part by weight of magnesium acetate tetrahydrate was used in Example 10.Tables 1 and 2 show the results.

Example 17

Procedures were carried out in the same manner as in Example 10, exceptthat the titanium tetrabutoxide was changed and the catalyst prepared inReference Example 1 in an amount of 30 mmole % expressed in terms oftitanium atom was used in Example 10. Tables 1 and 2 show the results.

Example 18

Procedures were carried out in the same manner as in Example 10, exceptthat the titanium tetrabutoxide was changed and the catalyst prepared inReference Example 2 in an amount of 30 mmole % expressed in terms oftitanium atom was used in Example 10. Tables 1 and 2 show the results.

Example 19

Procedures were carried out in the same manner as in Example 10, exceptthat 0.009 part by weight of trimethyl phosphate was added into thereaction system just after completing the transesterification in Example10. Tables 1 and 2 show the results.

Example 20

The chips obtained by procedures in Example 10 were melted at 250° C.with an extrusion spinning machine equipped with a spinneret providedwith 36 circular spinning holes having a hole diameter of 0.27 mm andspun at a throughput of 36 g/min and a takeoff speed of 3600 m/min, andthe resulting undrawn yarn was fed to a drawing treating machineequipped with a heating roller at 60° C. and a plate heater at 160° C.and subjected to drawing treatment at a draw ratio of 1.7 times toprovide an 83 dtex/36 filament drawn yarn. Tables 1 and 2 show theresults.

Example 21

The chips obtained by procedures in Example 10 were melted at 250° C.with an extrusion spinning machine equipped with a spinneret providedwith 36 circular spinning holes having a hole diameter of 0.27 mm andspun at a throughput of 34 g/min and a takeoff speed of 2400 m/min, andthe resulting undrawn yarn, without being wound once, was fed to adrawing treating machine equipped with a heating roller at 60° C. and aplate heater at 160° C. and subjected to drawing treatment at a drawratio of 1.7 times to afford an 83 dtex/36 filament drawn yarn. Tables 1and 2 show the results.

Comparative Example 1

Procedures were carried out in the same manner as in Example 1, exceptthat 0.0525 part by weight of the titanium tetrabutoxide was used tocarry out transesterification without using manganese acetatetetrahydrate and polymerizing reaction was then conducted withoutconducting further addition at all in Example 1. Table 1 shows theresults.

Comparative Example 2

Procedures were carried out in the same manner as in Example 1, exceptthat the amount of the added manganese acetate tetrahydrate was changedto 0.0885 part by weight in Example 1. Tables 1 and 2 show the results.

Comparative Example 3

Procedures were carried out in the same manner as in Example 6, exceptthat the amount of the added trimethyl phosphate was changed to 0.027part by weight in Example 6. Tables 1 and 2 show the results.

Comparative Example 4

Procedures were carried out in the same manner as in Example 10, exceptthat the amount of the added potassium acetate was changed to 0.0405part by weight in Example 10. Tables 1 and 2 show the results.

Comparative Example 5

Procedures were carried out in the same manner as in Example 10, exceptthat the amount of the added trimethyl phosphate was changed to 0.027part by weight in Example 10. Tables 1 and 2 show the results.

TABLE 1 Polymer (2) P/M (8) (9) (1) mmole % (3) (4) (5) (6) Molar % by %by (10) Kind mmole % Kind (11) mmole % ppm ppm ppm Ratio (7) weightweight b value Ex. 1  Mn(OAc)₂·4H₂O 25 TBT 30 — — — 66 0.0 0.75 0.23 2.06.8 Ex. 2  Mn(OAc)₂·4H₂O 25 TBT 30 — — — 66 0.0 0.75 0.23 2.1 4.9Co(OAc)₂·4H₂O 3 Ex. 3  Mn(OAc)₂·4H₂O 25 TMT 30 — — — 66 0.0 0.75 0.252.1 6.5 Ex. 4  Mn(OAc)₂·4H₂O 25 TPO 30 — — — 66 0.5 0.75 0.26 2.0 6.0Ex. 5  Mn(OAc)₂·4H₂O 25 TPI 30 12.5 — — 66 0.5 0.75 0.24 2.1 6.2 Ex. 6 Mn(OAc)₂·4H₂O 25 TBT 30 12.5 — — 66 0.5 0.75 0.23 2.0 5.9 Ex. 7 Mn(OAc)₂·4H₂O 25 TBT 30 — — — 66 0.5 0.75 0.24 2.1 4.8 Co(OAc)₂·4H₂O 3Ex. 8  Mn(OAc)₂·4H₂O 25 TBT 30 — — — 66 0.0 0.75 0.23 2.0 6.8 Ex. 9 Mn(OAc)₂·4H₂O 25 TBT 30 — — — 66 0.0 0.75 0.23 2.0 6.8 Ex. 10 KOAc 25TBT 30 — 51 — — 0.0 0.75 0.21 2.1 6.6 Ex. 11 KOAc 15 TBT 30 — 31 — — 0.00.75 0.22 2.0 5.0 Ex. 12 Na(OAc)₂3H₂O 25 TBT 30 — 51 — — 0.0 0.75 0.232.1 6.0 Ex. 13 LiOAc 25 TBT 30 —  9 — — 0.0 0.75 0.22 1.9 5.5 Ex. 14RbOAc 25 TBT 30 — 111  — — 0.0 0.75 0.24 2.1 7.2 Ex. 15 Ca(OAc)₂.H₂O 25TBT 30 — — 52 — 0.0 0.75 0.23 2.2 6.0 Ex. 16 Mg(OAc)₂·4H₂O 25 TBT 30 — —32 — 0.0 0.75 0.21 2.0 5.6 Ex. 17 KOAc 25 TMT 30 — 51 — — 0.0 0.75 0.222.1 6.7 Ex. 18 KOAc 25 TPO 30 — 51 — — 0.0 0.75 0.20 2.1 6.8 Ex. 19 KOAc25 TBT 30 12.5 51 — — 0.5 0.75 0.21 1.9 5.5 Ex. 20 KOAc 25 TBT 30 — 51 —— 0.0 0.75 0.21 2.1 6.6 Ex. 21 KOAc 25 TBT 30 — 51 — — 0.0 0.75 0.21 2.16.6 (12) TBT 30 — — — — — — — 0.75 0.21 2.0 5.1 (13) Mn(OAc)₂·4H₂O 70TBT 30 — — — 185  0.0 0.75 0.25 2.1 10.5 (14) Mn(OAc)₂·4H₂O 25 TBT 3037.5 — — 66 1.5 0.75 0.22 2.0 5.5 (15) KOAc 70 TBT 30 — 142  — — 0.00.75 0.25 2.1 10.5 (16) KOAc 25 TBT 30 37.5 51 — — 1.5 0.75 0.22 2.0 5.5Notes: Abbreviations in the table mean each the following.Mn(OAc)₂·4H₂O: Manganese acetate tetrahydrate Co(OAc)₂·4H₂O: Cobaltacetate tetrahydrate KOAc: Potassium acetate NaOAc·3H₂O: Sodium acetatetrihydrate LiOAc: Lithium acetate RbOAc: Rubidium acetate Ca(OAc)₂.H₂O:Calcium acetate monohydrate Mg(OAc)₂·4H₂O: Magnesium acetatetetrahydrate DPG: Dipropylene glycol TBT: Titanium tetrabutoxide TMT: Areaction product of titanium tetrabutoxide-trimellitic anhydride in amolar ratio of 1/2 TPO: A reaction product of titaniumtetrabutoxide-phenylphosphonic acid in a molar ratio of 1/2 TPI: Areaction product of titanium tetrabutoxide-phenylphosphinic acid in amolar ratio of 1/2 (1) means “Transesterification Catalyst”. (2) means“Polymerizing Reaction Catalyst”. (3) means “Trimethyl Phosphate”. (4)means “Content of Alkali Metal Element”. (5) means “Content of AlkalineEarth Metal Element”. (6) means “Content of Manganese Element”. (7)means “Intrinsic Viscosity”. (8) means “Content of DPG”. (9) means“Content of Cyclic Dimer”. (10) means “Color after Crystallization”.(11) means “(Expressed in Terms of Ti atom)”. (12) means “ComparativeExample 1”. (13) means “Comparative Example 2”. (14) means “ComparativeExample 3”. (15) means “Comparative Example 4”. (16) means “ComparativeExample 5”. Ex. means “Example”.

TABLE 2 Drawn Yarn Light Resis- (1) (5) tance of Fabric m/ (2) (4) cN/(6) Color b value min Times (3) dtex dtex % (7) (8) (9) Example 1  24001.7 0.72 83 3.1 40 2.7 2.9 0.2 Example 2  2400 1.7 0.71 83 3.0 42 2.32.6 0.3 Example 3  2400 1.7 0.71 83 2.9 41 2.6 2.9 0.3 Example 4  24001.7 0.72 83 3.1 40 2.5 3.0 0.5 Example 5  2400 1.7 0.71 83 3.2 43 2.43.0 0.6 Example 6  2400 1.7 0.72 83 3.0 40 2.4 3.0 0.6 Example 7  24001.7 0.71 83 3.1 40 2.1 2.8 0.7 Example 8  3600 1.2 0.71 83 3.1 42 2.83.0 0.2 Example 9  2400 1.7 0.71 83 3.0 43 2.7 3.0 0.3 Example 10 24001.7 0.71 83 3.1 40 2.6 2.7 0.1 Example 11 2400 1.7 0.72 83 3.0 42 2.42.7 0.3 Example 12 2400 1.7 0.71 83 2.9 41 2.3 3.3 1.0 Example 13 24001.7 0.72 83 3.1 40 2.3 3.4 1.1 Example 14 2400 1.7 0.71 83 3.2 43 3.02.7 −0.3 Example 15 2400 1.7 0.72 83 3.0 40 2.0 3.0 1.0 Example 16 24001.7 0.71 83 3.1 40 2.1 3.3 1.2 Example 17 2400 1.7 0.72 83 3.0 41 2.72.8 0.1 Example 18 2400 1.7 0.72 83 3.0 39 2.5 2.8 0.3 Example 19 24001.7 0.71 83 3.1 40 2.3 2.6 0.3 Example 20 3600 1.2 0.71 83 3.1 42 2.72.8 0.1 Example 21 2400 1.7 0.71 83 3.0 43 2.7 2.9 0.2 (10) 2400 1.70.73 83 3.3 42 2.2 4.7 2.5 (11) 2400 1.7 0.71 83 2.9 39 5.6 5.8 0.2 (12)2400 1.7 0.72 83 3.1 41 2.5 4.7 2.2 (13) 2400 1.7 0.71 83 2.9 39 5.6 5.80.2 (14) 2400 1.7 0.72 83 3.1 41 2.5 4.7 2.2 Notes: (1) means “SpinningSpeed”. (2) means “Draw Ratio”. (3) means “Intrinsic Viscosity”. (4)means “Fineness”. (5) means “Tensile Strength”. (6) means “TensileElongation”. (7) means “Before Light Irradiation”. (8) means “AfterLight Irradiation”. (9) means “Increase before and after Irradiation”.(10) means “Comparative Example 1”. (11) means “Comparative Example 2”.(12) means “Comparative Example 3”. (13) means “Comparative Example 4”.(14) means “Comparative Example 5”.

INDUSTRIAL APPLICABILITY

According to the present invention, there can be provided a polyesterbased on poly(trimethylene terephthalate) capable of improving lightresistance of the polyester based on the poly(trimethyleneterephthalate) and suitable for producing formed products responsive towide demands because forming conditions such as yarn manufacturingconditions are not strictly limited. The industrial significance of thepresent invention is great.

1. A polyester based on poly(trimethylene terephthalate) consistingessentially of trimethylene terephthalate repeating units, comprising atleast one kind of compound selected from the group consisting ofmanganese compounds in an amount of 10 to 150 ppm expressed in terms ofthe manganese element, and the molar ratio of the amount of the totalamount of elements of the contained manganese element to the amount ofthe contained phosphorus element is within the range of the followingformula (I):0≦P/M≦1  (I) wherein, P is the molar amount the phosphorus element inthe polyester; M is the total molar amount of manganese element, andwherein the content of a cyclic dimer is within the range of 0.01 to2.2% by weight based on the total weight of the polyester.
 2. Thepolyester according to claim 1, wherein the following respectiverequirements (a) to (d) are simultaneously satisfied, (a) the intrinsicviscosity is within the range of 0.5 to 1.6, (b) the content ofdipropylene glycol is within the range of 0.1 to 2.0% by weight based onthe total weight of the polyester, and (c) the color b value is withinthe range of −5 to
 10. 3. The polyester according to claim 1, whereinthe manganese compounds are compounds selected from the group consistingof manganese acetate, manganese benzoate and manganese chloride.
 4. Amethod for producing a polyester based on poly(trimethyleneterephthalate) comprising using a titanium compound as a polymerizationcatalyst when the polyester according to claim 1 is produced.
 5. Themethod for production according to claim 4, wherein the titaniumcompound is a titanium tetraalkoxide.
 6. The method for productionaccording to claim 4, wherein the titanium compound is a reactionproduct of at least one compound selected from the group consisting ofphthalic acid, trimellitic acid, hemimellitic acid and pyromellitic acidor anhydrides thereof with a titanium tetraalkoxide.
 7. The method forproduction according to claim 4, wherein the titanium compound is areaction product of a titanium tetraalkoxide with a phosphonic acidcompound.
 8. The method for production according to claim 4, wherein thetitanium compound is a reaction product of a titanium tetraalkoxide witha phosphinic acid compound.
 9. The method for production according toclaim 4, wherein the titanium compound is a reaction product of atitanium tetraalkoxide with a phosphate compound.
 10. The method forproduction according to claim 4, wherein the titanium compound is areaction product of a reaction product between at least one compoundselected from the group consisting of phthalic acid, trimellitic acid,hemimellitic acid and pyromellitic acid or anhdyrides thereof and atitanium tetraalkoxide with a phosphonic acid compound.
 11. The methodfor production according to claim 4, wherein the titanium compound is areaction product of a reaction product between at least one compoundselected from the group consisting of phthalic acid, trimellitic acid,hemimellitic acid and pyromellitic acid or anhydrides thereof and atitanium tetraalkoxide with a phosphinic acid compound.
 12. The methodfor production according to claim 4, wherein the titanium compound is areaction product of a reaction product between at least one compoundselected from the group consisting of phthalic acid, trimellitic acid,hemimellitic acid and pyromellitic acid or anhydrides thereof and atitanium tetraalkoxide with a phosphate compound.
 13. Polyester fibersbased on poly(trimethylene terephthalate) which are obtained by meltspinning the polyester based on the poly(trimethylene terephthalate)according to claim 1 at a melting temperature of 238 to 275° C. and aspinning speed of 400 to 5000 m/mm.
 14. A polyester drawn yarn based onthe poly(trimethylene terephthalate) obtained after winding the fibersaccording to claim 13 once or without winding the fibers once andcontinuously subjecting the fibers to drawing treatment.
 15. A fabricwhich is composed of a polyester comprising the polyester fibers basedon the poly(trimethylene terephthalate) according to claim 13 and has anincrease in color b value of 2 or below after irradiation at 60° C. for80 hours using a sunshine weatherometer.
 16. A fabric which is composedof a polyester comprising the polyester drawn yarn based on thepoly(trimethylene terephthalate) according to claim 13 and has anincrease in color b value of 2 or below after irradiation at 60° C. for80 hours using a sunshine weatherometer.